1. Energy Efficiency in Buildings: Business Realities and Opportunities;World Business Council for Sustainable Development,2007
2. Fundación Entorno-Spanish Business Council for Sustainable Development, Construimos Valor, Incentivos a la Construcción Sostenible [Building Values, Incentives for Sustainable Construction], Spain, 2007, available at http://www.fundacionentorno.org/ (in Spanish).
3. Las emisiones de gases de efecto invernadero por Comunidades Autónomas en España en 2007;Rodrigo,2008
4. Spanish National Association of Aggregates Producers, Estadísticas de áridos 2006 [Aggregate Statistics 2006], Spain, 2007, available at http://www.aridos.org/ (in Spanish).
5. Data from Group Alfonso Gallardo, Balboa Cements.